OpenBuilds approached me to create a conversion for the MiniMill to turn it into a 3D Printer. They supplied a standard MiniMill kit, 3 standard Nema 23 stepper motors, 24V Meanwell power supply w/ OB Power Case kit, OB wiring kit and 3 limit switch kits. They also supplied a Duet 2 WiFi in their OpenCase mounting system and a 24V E3D Titan Aero kit.
I realized early on that the standard OpenBuilds MiniMill kit offered minimally useful Z height for a 3D printer, but it could be an excellent small laser engraver. That is why I added a laser engraver head to the conversion - making this a 3-in-1 conversion.
Hence the name, Triple Threat! The laser diode that I added is the L-Cheapo 10 watt version. It will run off of either 12V or 24V supply and has enough power to cut and engrave most wood, acrylic (not clear) and can etch on anodized aluminum.
The STL files attached can be used to reproduce the 3D printer conversion mounts and the laser engraver conversion mount. The mill/router portion would still require the normal spindle or handheld style router. The Duet RepRap firmware is capable of handling all three modes of operation and each mode can be called using the g-code.
The one thing that the Duet 2 WiFi requires to work properly with PWM laser control is a signal inverter. A link to the circuit hardware required is on the Duet Wiki here. I opted to have a prototype board produced by OSHPark and soldered it up myself. It plugs directly into the Duet 2 WiFi and only requires 24V power input and output wires to the laser diode control board.
You can read more about the project on the OpenBuilds build website here.
DeltaForce (original custom delta)
Atomic PETG (carbon fiber filled)
I used carbon fiber filled PETG from Atomic for 4 reasons... it looks incredible (this was to be a show machine), it prints really nice with a hardened nozzle, I had this material in ample supply (thanks to Mike from MRRF2018), and it is incredibly durable and rigid.
These files could just as easily be printed in ABS or something like PLA-Pro (just be aware of possible heat issues with the cooler ring).
Several M3 socket head cap screws / nuts and M5 ultra low head screws / locking hex nuts are required. Pockets are provided to capture the hex nuts for assembly ease.
Mount for E3D Titan Aero on the OpenBuilds Spindle mount
Print bed mounting blocks and spacers (this will fit the OpenBuilds Mini Heated Bed)
Part cooling ring - attached to OpenBuilds Spindle mount
Laser module ready to be mounted
Meanwell PS mounted under the main MiniMill frame
Outrigger to raise the MiniMill up for undermounting the power supply. It also adds stability.
Duet 2 WiFi mounted in OpenCase (PWM board and PanelDue cable also shown)
Close-up of the PWM board required for the Duet 2 WiFi laser control
Overall build of Triple Threat in 3D Printer form (minus the print bed)